Real world ET expectations on new build

598 C Headed motor going into a 4link dragster. Weight with 557 BT headed motor was 1975 lbs with driver. 4.33 gear ran 7.80's @ 169 7700 rpm. Based on the threads I have seen I belive 1100 HP is realalistic. However, I belive the new block and head combo will push weight to 2150 lbs. I think a 4.10 gear is in order and 7.40's @ 177 7700 rpm ?
Is my thinking correct? Can someone help?

are you gona dyno the 598?

Yes we are. Three weeks away I belive. Loking for corect rear gear, I think 7700 - 7800 is as tight as I want to spin it.

1markd wrote:Yes we are. Three weeks away I belive. Loking for corect rear gear, I think 7700 - 7800 is as tight as I want to spin it.

same thing i was thinken.lol.i dont have a rail so i wont give advice on the gear but some guys on here can for sure.i'm building a 605 and i would'nt want to spin it that high.

Assuming 2000ft density altitude for the 557 , it would have been around 750hp/650ftlb with a 33" rear tyre and 4.33 gears at that weight , 4000rpm launch with 5000 convertor.

Similar weight for the 598 , using a powerglide and 4.11 rear gears , 5000rpm launch with a 5500 stall , 1100hp/820ftlb , 2000ft of air , could go 7.3's at 190+ , through the traps at 7850rpm.

If you take that density down to 1000ft , 7.2's and 195mph.

So without a more accurate estimate of the 557 hp and tq , the above is my best guess , but should be pretty close as I ran 8.00@165 at 1880lbs with 720hp / 630ftlb in 1900ft air. Your dragster would have less resistance than my altered/hotrod.

I am hoping for 1100 -1200hp from my alcohol all aluminium 572ci Boss9 Hemi , to get low low 7's at 190mph + , 8200rpm across the finish.

Good luck on the dyno,

John